The present invention relates to thermally insulated containers, and, more particularly, to insulated containers which are collapsible for smaller storage or shipping for reuse. A collapsible insulated container breaks down to allow it to be stored or boxed and shipped, by having some or all of the edges of the container be separable. If only some edges are separable, the remaining edges are flexible, allowing for folding of the side walls.
Collapsible insulated containers have a number of advantages over fixed wall thermally insulated containers. The walls of the collapsible containers can be folded such as when not in use or broken down to fit into a small area or shipping box. Collapsible containers are generally light weight. Though the use of collapsible containers may involve vigorous wear and tear, collapsible containers can be made durable and attractive for multiple uses over an extended period of time. In industries where product must be kept cold and shipped overnight or over a short period of time, such collapsible containers are often preferable to containers with fixed walls, because they can be collapsed during return shipment and non-use.
While collapsible containers have many advantages, the very nature of the container leads to a number of problems as compared to fixed wall containers. The collapsible container must have either flexible side walls or separable side walls to allow for folding of the container. Separable sidewalls can lead to thermal problems including the escape of heat or cold from the container through gaps between the sidewalls, the base and/or the cover. In addition, the relative fit of the separable edges of the container is determined for each use upon set-up, precise dimensions may vary and thermal problems may vary from use to use.
The design of the collapsible container needs to be efficient and inexpensive, from the stand point of both the cost of the materials and the amount of the materials used. The collapsible container should also be easy to manufacture. In addition, depending on the type of thermal insulation used, the insulation of the collapsible container may be damaged or punctured during use. And finally, the container must be easy to assemble such that potential thermal problems are minimized during the set-up process.